/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package at.irian.demo.jsfatwork.view.exception;

import at.irian.demo.jsfatwork.service.exception.ServiceException;
import at.irian.demo.jsfatwork.view.MessageBean;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.context.annotation.Lazy;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import javax.faces.application.FacesMessage;
import javax.faces.context.FacesContext;
import javax.inject.Inject;

/**
 * Aspect around all public methods in page beans which provides a 
 * simple exception handling mechanism.
 *
 * @author Gerhard Petracek
 */
@Aspect
@Lazy
@Component
@Order(0)
public class UIExceptionInterceptor
{
    @Inject
    private MessageBean messageBean;

    @Around("execution(public * at.irian.demo.jsfatwork.view.page..*.*(..))")
    public Object handleException(ProceedingJoinPoint pjp) throws Throwable
    {
        FacesContext facesContext = FacesContext.getCurrentInstance();

        try
        {
            return pjp.proceed();
        }
        catch (UILockDownException le)
        {
            facesContext.getApplication().getNavigationHandler().handleNavigation(facesContext, null, "pages/lock");

            this.messageBean.addMessage(FacesMessage.SEVERITY_FATAL, le.getMessage());
        }
        catch (ServiceException se)
        {
            this.messageBean.addMessage(FacesMessage.SEVERITY_ERROR, se.getMessage());
            return null;
        }
        catch (Throwable e)
        {
            handleExternalException(facesContext, e);
        }
        return null;
    }

    private void handleExternalException(FacesContext facesContext, Throwable e)
    {
        e.printStackTrace();

        facesContext.getApplication().getNavigationHandler().handleNavigation(facesContext, null, "pages/error");

        this.messageBean.addMessage(FacesMessage.SEVERITY_FATAL, "unknown_error");
    }
}